Gold Label 60/40 45L — RHP-Certified Hydroponic Growing Medium
Best for: Hydroponic growers who want the drainage of clay pebbles with the water retention safety net of coco, without faffing about with preparation
Our thoughts
Gold Label got there first with the 60/40 blend, and they've kept it dialled in ever since. Twenty-plus years of development shows — this is the only RHP-certified coco-pebble mix built specifically for hydroponics. Ready to use straight out the bag, and it works with everything from hand watering to Wilma and AutoPot systems. One a lot of commercial growers reach for.
Gold Label HydroCoco 60/40 is a pre-mixed hydroponic growing medium combining 60% expanded clay pebbles with 40% buffered coco coir, designed specifically for fast-draining hydroponic systems. It gives you the excellent drainage and root support of clay with the water retention and nutrient-holding properties of coco — all ready to use, no washing or soaking required. Out of the bag and straight into your system.
How it compares
The 60/40 blend sits in a smart middle ground between pure substrates.
-
vs pure clay pebbles: Holds more water, so you don't need to feed quite as often. Less risk if a pump fails
-
vs pure coco coir: Drains faster, prevents waterlogging, reduces root disease risk in hydroponic systems
-
vs rockwool: Reusable indefinitely, more cost-effective long-term, easier to manage pH
-
RHP certified: Only certified 60/40 blend on the UK market — coco is cleaned, buffered, and EC below 0.6
Usage guidance
This medium works across most hydroponic setups.
Flood and drain systems
Pour straight into trays. Pre-moisten with pH-adjusted water (5.5–6.5) before planting. The 40% coco retention means plants will drain to roughly half their fully-watered weight before needing the next flood cycle.
Drip irrigation and run-to-waste
Works cleanly in IWS, Multiflow, Wilma, and similar systems. Water less frequently than you would with pure clay — coco's water-holding keeps roots fed between cycles.
Hand watering and AutoPot
Ideal for passive hydroponic systems where you're not running pumps. The blend reduces watering frequency and gives you a safety net if feeding lags.
Nutrient feeding
Use hydroponic nutrients designed for your system (not general purpose). Coco holds nutrients longer than clay, so adjust feed schedules accordingly. Test pot weight before watering — that's your guide.
Aftercare
This medium is fully reusable. Mix in fresh substrate between crops and you can keep using it for years.
Technical specifications
- Volume: 45 litres (marketed as such; physical capacity 50L)
- Composition: 60% expanded clay pebbles (8–12mm), 40% buffered coco coir
- pH: Neutral (5.5–6.5 range)
- EC: Less than 0.6 mS/cm (very clean, minimal salt content)
- Certification: RHP and Kiwa certified — only RHP-certified 60/40 blend for hydroponics
- Nutrient additives: None — you control feeding completely
- Preparation: Ready to use straight from bag — no washing, soaking, or flushing required
- Dimensions: 62cm (L) × 41cm (W) × 15cm (H)
- Weight: Approximately 15kg per bag
Who this is for
- Hydroponic growers running flood and drain, drip, or passive systems
- Anyone switching from pure clay pebbles who wants less frequent watering
- Commercial and hobby growers who value certification and proven reliability
- Growers using AutoPot, Wilma, IWS, or Multiflow systems
- Budget-conscious growers planning long-term — this substrate is reusable indefinitely
Our take
Twenty years of product development and RHP certification backs this up. Gold Label 60/40 does what a hydroponic growing medium should: drains properly, holds enough moisture to reduce feeding frequency, and doesn't require any messing about before use. It's the blend that started the 60/40 conversation in the UK, and for good reason.
Whether you're hand watering or running a multi-system setup, this covers the job properly without overcomplicating things. Worth picking up while stock lasts.
